Such processes and apparatuses are generally known and conventional and are described in particular in the applicant's following patent applications: DOS No. 25 09 411, DOS No. 27 37 049, DOS No. 27 58 411 and DOS No. 28 47 146. The disclosure of those specifications is hereby expressly incorporated in the present application.
In such exhaust gas emission tests, using the idle-acceleration method, in principle the internal combustion engine for example of a motor vehicle is put into the transmission idle position and the motor is then accelerated from an idle speed to a higher speed, by increasing the supply of fuel. In that operation, the torque produced by the engine causes acceleration of the masses of the engine and possibly a part of the transmission. In particular the rotary inertia of the crankshaft, the clutch plate and the flywheel permits effective loading of the engine, which simulates operating conditions (mean pressure). With these test methods, the frictional losses of the engine are either disregarded or taken into account, by means of a given factor, in the analysis or evaluation step. The moments of inertia which occur in the engine, and the torque produced, may be represented in the following manner: EQU J.sub.total =J.sub.engine +J.sub.transmission ; EQU .phi.=(d.omega./dt) EQU M.sub.engine =J.sub.total .multidot..phi.
Instead of measuring exhaust gas emission, it is possible also to measure all other functions of the engine, which are dependent on load, such as for example noise emission or fuel consumption (that may be ascertained in known manner indirectly by measurement of the hydrocarbons in the exhaust gases).